Refactor tests/db/create_service() to behave more like the real world.
Created new create_service_with_inbound_number and create_service_with_defined_sms_sender() test/db methods.
When a service is allocated an inbound number and they only have one SMS sender, then update that SMS sender to the inbound number.
That way they will not have more than one SMS sender and will not have to choose to use either one.